Question

大家好我已经尝试过这段代码，但它没有用。我无法插入并从数据库sqlite android中选择。

问题：我错了吗？

代码：

public class Test extends SQLiteOpenHelper {

private static final String DATABASE_CREATE = "CREATE TABLE PLS (" + 
         "id text, " + 
         "nama text);";

public Test(Context context) {
    super(context, "ABC.db", null, 1);
    // TODO Auto-generated constructor stub
}


@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub
    db.execSQL(DATABASE_CREATE);
    db.execSQL("INSERT INTO PLS VALUES('1', 'dede');");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub
    db.execSQL("DROP TABLE IF EXISTS PLS");
    onCreate(db);
}

public ArrayList<HashMap<String, String>> getUser() {
    ArrayList<HashMap<String, String>> wordList;
    wordList = new ArrayList<HashMap<String, String>>();
    String selectQuery = "SELECT id, nama FROM PLS";
    SQLiteDatabase database = this.getWritableDatabase();
    Cursor cursor = database.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
      do {
        HashMap<String, String> map = new HashMap<String, String>();
        map.put("id", cursor.getString(0));
        map.put("nama", cursor.getString(1));
      } while (cursor.moveToNext());
    }
    return wordList;
}

public void addUser(String id, String nama) {
    SQLiteDatabase database = this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put("id", id);
    values.put("nama", nama);
    database.insert("PLS", null, values);
    database.close();
  }
}

以下是插入和选择sqlite的代码：

    controller = new Test(this);
    user = new ArrayList<HashMap<String,String>>();
    controller.addUser("1", "daniel");

    user = controller.getUser();

    for(int i=0; i<user.size(); i++){
        tempMenu = new HashMap<String, String>();
        tempMenu = user.get(i);
        i1.setText(tempMenu.get("id"));
        i2.setText(tempMenu.get("nama"));
    }

Answer 1

我认为你的代码是正确的，除了你忘了填充wordList变量！在getUser（）函数返回之前...

if (cursor.moveToFirst()) {
  do { 
    HashMap<String, String> map = new HashMap<String, String>();
    map.put("id", cursor.getString(0));
    map.put("nama", cursor.getString(1));
    //Here you forgot wordList.add(map);
  } while (cursor.moveToNext());
}

android sqlite无法插入和选择

1 个答案: